In recent years, advancing of an ink-jet technique is remarkable and is combined with development of a printer technique, an ink technique, a technique of a recording medium for exclusive use for an ink-jet recording so that an image quality provided by them becomes refer to as photographic-quality. With enhancement of image quality, preservation of ink-jet image becomes to compare with a conventional silversalt photography, in particular, in dye-based ink, deterioration with transfer of a color agent such as weakness ink-jet image in water resistance of and blur resistance, deterioration with chemical reaction of color agent characteristic such as weakness in light resistance and oxidation gas resistance are pointed out.
Especially, in recent years, color deterioration of ink-jet recording image by ozone gas included in trace within atmosphere becomes a problem.
In a purpose of image conservation enhancement of recording image by the dye-based ink which the problem is mentioned above, a trial to form a layer by resin on an imaging surface has been made.
For example, in Japanese Patent Laid-Open No. 59-222381, Japanese Patent Laid-Open No. 4-21446, 10-315448, 11-5362, 11-192775, the thermoplastic organic polymer particle layer is made for the most surface layer of an ink-jet recording medium, then, after image recording, this thermoplastic organic polymer particle is fused to become a layer, as a result, water resistance, a weatherproof upgrade and a glossiness grant of image are achieved by forming protective layer of polymer.
According to this method, although some effect is observed in image conservation enhancement, an application of heat fuser for exclusive use of an exclusive ink-jet recording medium being necessary becomes necessary, and, in addition, a blister by evaporation of an ink solvent occurs in application of heat fixing, fusing, and film let-go occurs, and control holds learning activity that it is difficult. Further the thermoplastic organic polymer grain layer of the most outermost layer comprises defect obstructing ink absorbency.
On the other hand, TOKKAI No. S55-18412 and No. H11-199808 offer a method of improving water resistance and light resistance of ink by adding fine particles of latex or resin.
Further, TOKKAI No. 2001-187852 and No. 2002-240413 disclose adding of resin to ink to improve ozone resistance of the ink. Still further, TOKKAI No. 2002-80759, 2002-194253, 2002-264490, 2002-285049, and 2003-55586 disclose a technology of adding fine particles of latex or resin to ink.
Although a method of adding fine particles of latex or resin to ink has an effect on preventing color deterioration caused by ozone gas, to a certain degree, it has been proved that the method has the following problem.
The first problem is that the glossiness of parts provided with ink is increased, and that of white background parts remain unchanged. As a result, differences in glossiness between image parts and non-image parts can be caused. The second problem is that although a satisfying effect on preventing color deterioration caused by ozone gas can be recognized in high concentration parts and in an intermediate concentration parts with a large amount of ink, the effect to parts provided with a small amount of ink is not enough. Consequently, deterioration in the parts provided with a small amount of ink becomes even more apparent. Or, although a satisfying effect on preventing color deterioration due to ozone gas can be recognized in parts in a secondary color or a multidimensional color, the effect to parts in a nearly saturated color, concretely, to parts in cyan or magenta color is not enough. Thus, color deterioration in a nearly saturated color becomes apparent, hereby the degree of color deterioration differs depending on scenes in an image, which makes an unnatural image.
The third problem is that, in image parts neighboring white background parts, effect of preventing color deterioration caused by harmful gasses such as ozone gas is not achieved enough. It is understood that this is caused by entry of ozone gas from neighboring white background parts and diffusion into image parts.
As a solution of the above problems, TOKKAI No. H09-262971, 2000-225695, and 2000-335043 disclose a technology of providing a laminating agent on an image to improve the preservability of the image. This technology can be understood to be a technology of providing a laminating agent on an entire image. However, in parts provided with a large amount of recording ink, this technology causes an image degradation and a decrease in glossiness due to spilling of ink, and even worsens color deterioration, which could be improved otherwise, wherein the technology is not successful in solving the problems described in the present invention.
Also, International Patent No. 00/06390 and TOKKAI 2001-39006 disclose a technology of providing a liquid containing colorless fine resinous particles on parts with a large amount of ink deposited thereon, to improve the preserving ability or glossiness of an image. However, by this technology, differences in glossiness depending on parts in a print are not prevented, and the effect on preventing color deterioration due to ozone gas in image parts neighboring white background parts is not obtained, further resulting in degradation in image quality and glossiness due to spilling of ink in parts provided with recording ink.
On the other hand, there is disclosed a technology of providing colorless ink into regions where ink is not provided. For example, there is disclosed a technology in which ink containing a coloring agent, a resin emulsion, and sugar is deposited on a recording medium that is a transparent base material provided with a porous ink receiving layer thereon, and clear ink having a reflective index with a difference of 0.1 or less from that of the above ink is recorded on blank parts where color ink is not recorded, thereby forming an image with a high transparency (for example, refer to TOKKAI No. H08-85218). Further, there is also disclosed a technology of reducing the distortion of ruled lines in a low humidity environment by compensation with colorless ink to achieve a predetermined recording rate in regions surrounding an image (for example, refer to TOKKAI No. 2001-47644).
Further, there is disclosed a black and white image forming method that improves the graininess and sharpness by providing non-image parts with colorless ink containing fine resinous particles, when using special black inks of more than one kind having different concentrations (for example, refer to TOKKAI No. 2001-277488). However, in these disclosed technologies, there is no description that evenness in glossiness and resistance to color deterioration due to ozone gas in an image, which is a problem described in the present invention, is improved, and also, effects obtained by these technologies are not enough.
Also, in International Patent No. 03/24723A1, there is disclosed a method that uses a recording medium containing thermoplastic resinous particles and performs a heating process after recording, wherein a colorless or white colored liquid is provided on a print before the heating process. However, there is no description that the method improves evenness in color deterioration due to ozone gas in an image. Further, there are limitations by the requirement for a dedicated heat-processing unit, the requirement for a dedicated recording medium, and others.
There is also offered a method for reducing differences in glossiness appearance by providing parts complementary to a visible image with ink that keeps the color tone of a recording material unchanged (for example, refer to TOKKAI 2003-191601). Further, there is a description that since exposure of a recording material is reduced by this method, it is expected that light resistance and ozone resistance are improved. However, there is no suggestion for a specific solution to eliminate unevenness in color deterioration caused by ozone, which is possible as a result of effects on preventing development of color deterioration due to ozone in highlighted parts and monochromatic parts, and preventing color deterioration due to ozone in image parts, which is a problem recognized in the present patent application. In embodiments, also, there are various limitations by a requirement for a dedicated unit for adding a photo-curing chemical compound to recording ink to perform photo-curing processing on a print, and by others.
The present invention has been devised taking the above problems into account. The first object of the invention is to provide an ink-jet recording method and recorded matter that are excellent in evenness in color deterioration, which is realized by reducing color deterioration caused by harmful gases such as ozone gas, in various concentration regions and in image regions in different colors. The second object of the invention is to provide an ink-jet recording method and recorded matter that reduce differences in glossiness in a print. The third object of the invention is to provide an ink-jet recording method and recorded matter that improve evenness in color deterioration caused by ozone and in glossiness, as described above, without performing specific post-processing on a print, such as heating, pressing, or projecting light. The fourth object of the invention is to provide an ink-jet recording method and recorded matter that reduce degradation in image quality caused by generation of leakage or beads of ink, or the like.